Propeller mounting



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' PROPELLER MOUNTING l Filed Dec. 31,.1945 K 2 Sheets-Sheet 2 ,iz/farne? Patented May 3, 1949 UNITED STATES PATENT OFFICE PROPELLER MOUNTING Elmer C. iiiekhaefer, Cedarburg, Wis.

Application December 3l., 1945, Serial No. 638,544

6 Ulaims. t

This invention relates to a propeller mounting for outboard motors and thelike.

The principal object of the invention is tc provide a simple and less costly cushioned mounting ior a propeller.

another object is to provide a shear pin construction for a cushioned mounting and in which the shear pins are held in place by the mounting.

Another object is to provide a mounting that nts directly upon the end of a plain shaft without requiring additional sleeves or the like.

Other objects and advantages appear hereinafter in the description of an embodiment of the invention illustrated in the accompanying drawings.

In the drawings:

Figure l is a side elevation of a lower housing and the propeller with parts of the housing broken away and sectioned;

Fig. 2 is a rear elevation of the propeller with the blade tips broken away;

Fig. 3 is a front elevation of the propeller with the blade tips broken away;

Fig. 4 is an axial section of the propeller with the blades broken away;

Fig. 5 is an axial section of the assembled propeller mounting; and

Fig. 6 is a transverse section taken on line 6-6 of Fig. 5.

The propeller comprises a plurality of blades I- cast integrally with a hollow circular hub 2.

The hub 2 has a maximum diameter at its forward end, corresponding to that of the propeller shaft housing 3 of the outboard motor, and curves inwardly toward its rear end to a minimum diameter approaching a point to give a stream lined effect as the outboard motor moves through the water.

The drive shaft 4 is supported horizontally in suitable bearings 5 in housing 3, and has its rear end extending axially into hub 2. y

A cushion member 6 of rubber or other suitable resilient material is inserted between the hub 2 and shaft 4 to transmit the driving force between the shaft and propeller. For this purpose the hub 2 is of substantially larger diameter than shaft 4 and the insert 6 fills the hub.

The insert 6 is rotationally interlocked with hub 2 by means of a plurality of longitudinal ribs E the insert tc hold the same in place. A snap ring sets into a circumferential groove I0 in the hub 2 and overlaps the plate 8 sufficiently to hold the latter in place.

The propeller assembly with the insert 6 in hub 2 is pushed onto the rear end of shaft 4 and is secured in piace by a pair of shear pins l which are driven through holes i2 in the hub, and extend through corresponding holes in shaft Il. rlhe shear pins ll are substantially shorter than the diameter of hub 2 so that the ends of the pins, after they are driven into place, are spaced radially inward from the hub to provide for the closing in of the rubber of insert about the ends of the pins for retaining the pins in place.

The holes in insert 6 for receiving the shear pins H are of small diameter so that the pins enlarge the holes and fit tightly therein. The closing of the rubber about the ends of the pins prevents iilling of the holes with corrosion products and protects the pins in service.

When it is desired to remove the propeller from shaft 4 a punch is employed to drive the shear pins through and out of thehub assembly, after which the assembly can be readily pulled from the shaft.

The shear pins Il serve to transmit rotary forces and also axial forces between the shaft 4 and insert 6. The pins may be designed to shear oi in case of emergency. For this purpose small metal inserts I3 may be molded in the rubber to receive the pins Il adjacent the shaft. 'I'he inserts I3 provide greater bearing surface between the pins H and the rubber member 6.

The axial opening in cushion member 6 for receiving shaft 4 is preferablyl longer than the shaft to provide an air pocket I4 at the end of the shaft into which the rubber may move during` iiexing in service.

An internally threaded hole l5 may be provided axially through the rear end of hub 2 for the insertion of a puller to remove the assembly from the shaft. A smaller threaded hole I6 may be provided axially in the rear end of shaft 4 for the insertion of a member for forcing the propeller assembly onto the shaft.

The invention may have various embodiments within the scope of the accompanying claims.

' The term rubber as employed in the claims is intended to include synthetic and natural rubber and various plastics and the like having the required characteristics for the purpose and constituting equivalents to rubber in service.

3 Iclalm:

-1. In a propeller mounting of the class de-- scribed, a drive shaft, a propeller having a hub, a resilient insert between the hub and shaft to transmit driving forces therebetween andhaving a radial hole therein opening outwardly from said shaft, means to secure said insert in the propeller hub, and a transverse pin passing through said shaft and into lthe radial hole in said insert for securing the insert against axial displacement in either direction on said shaft.

2. In a propeller mounting of the class described, a drive shaft, a propeller having a hub, a. resilient rubber insert between the hub and shaft to transmit driving forces therebetween andA having a radial hole therein opening outwardly from said shaft, means to secure said insert in the propeller hub, and at least one transverse shear pin passing through said shaft and into'the radial' hole in said Ainsert to secure the latter upon the shaft against axial displacement in either direction.

3, In a propeller mounting of the class described, a drive shaft, a propeller having a hub,

a resilient rubber insert between the hub and' shaft to transmit .driving-forces therebetween, means to secure said insert in the propeller hub, and at least one transverse shear pin passing through said shaft and into said insert to secure the latter upon the shaft, saidvhub having holes therein aligned with said pin providing for insertion and removalof the pin.

4. In a propeller mounting of the class described, a drive shaft, a propeller having a hub, a resilient rubber insert between the hub and shaft to transmit driving forces therebetween, means to secure said insert in the propeller hub, and at least one transverse shear pin passing through said shaft and into said insert to secure the latter upon the shaft, said hub having holes therein aligned with said pin providing for insertion and removal of the pin and said insert having small holes for receiving said pin and adapted to substantially close upon the ends of the pin to retain the pin in place.

5. In a propeller mounting of the class described, a drive shaft, a propeller having a hub, a resilient rubber insertl between .the hub and shaft to transmit driving forces therebetween, means to secure said insert in the propeller hub, at least one transverse shear pin passing through said shaft and into said insert to secure the latter upon the shaft, said hub having holes therein aligned with said pin providing for insertion and removal of the pin and said insert having small holes for receiving said pin and adapted to substantially close upon the ends of the pin to retain the pin in. place, and metal inserts at the inner ends of the holes in said rubber member for receiving said shear pin and providing additional` bearing surface between it and the rubber.

6. In a propeller mountingf of theclassy described, a drive shaft, a propeller havinga hub, a resilient rubber insert between the hub and shaft to transmit driving forces therebetween, means to secure said insert-in the propeller hub, at least onetransverse shear pin passing through said shaft and into said insert to secure the latter upon the shaft, said hub having holes therein aligned with said pin providing :for insertion and removal of the pin, and metal inserts disposed in said rubber member for receiving said shear pin and providing additional bearing surface between it and the rubber.

' ELMER.

REFERENCES CITED c. KIEKHAEFER.

The following references are of record in the le of this patent:

Y UNITED STATES PATENTS Number Name Date Yantis July 4, 1939 

